GP-4u

Introduction
The GP-4u kit (Civlian Gas Mask Type 4 upgraded/Гражданский противогаз типа 4 ) first introduced in 1955. This was the first civilian kit to be massivly produced, GP-4u kit spread across the country very qucikly and became the first most common Civilian gas mask in it's time. The production of GP-4u kit didn't stop even when the famous GP-5 kit got introduced in 1962, the GP-4u was produced up to 1974. GP-4u was a succsesor to GP-4 (that's why it is designated GP-4 upgraded).

This kit was copied by Poland and some other eastern bloc countries, Poland made many copies and different designs based of the original GP-4u/GP-4.

The Kit

 * M-49 facepiece (mask-49, 49 is the year when it was designed, the fact that both GP-4 and GP-4u's face pieces are different they still have a same designation)


 * GP-4u filter


 * Bag (possibly designated bag for GP-4u)


 * Anti-foggig stick KPZO ( КПЗО)

The Mask
Mask M-49 is very similar to Soviet MOD-0-8 gas mask which is almost exactly the same design. M-49 has a fixed non removable hose. It was the first Soviet Civilian gas mask to feature two exhale valves. eyepiece design is the veru generic Soviet one, the glass is placed in a round ridge then we have tape warpped around it and to add we have a metal ring with clamps. The hose is covered in canvas, both ends are secured with a layer of tape, then a metal ring and another layer of tape.The valve assembly is kept in the place with the same method as the hose, tape, metal ring and another layer of tape. The lenses fog up easily so using the anti-fogging stick is reccomended. M-49 features 6 point headharness, all points can be adjusted. M-49 comes in 3 different sizes 1 2 and 3. There were two headharness, beacsue the design changed a bit over the course of the years for the M-49 (later one had different parts) the earlies one's (1955-1965 estimated) had a headharness with a rubberized mesh piece and later ones didn't, it is said that it was removed because it was uncomfortable and without it the wearer would get a better seal. The exhale cover also changed just like the headharness, the earlier cover had more air holes and the later one featured less air holes. The markings on M-49 could appear on either side of the mask, sometimes on the left and sometimes on the right, markings are simple Factory machine number ф-..... | manufactuer is the letter infornt of the year marking most common could be Я 57... this means it was made in Yaroslav 1957 and the amount of dots tell us the quarter of the year of when it was made.

Filter GP-4u
The GP-4u filter can be used to filter harmful dust, fumes, gasses. The filter has 8 protruding rings all round it (earlier GP-4u filter has 6 and older GP-4 also has 6), these rings gave the filter better resistance to physical damage. top of the filter has a 40mm male GOST thread, the bottom is sealed with a rubber plug which is attached to the filter with a small string to you don't loose it. Markings on the filters do vary but these are the most common type of them:
 * 27-III-68-2 (Day-Month-yeah-uknown)
 * ГП-4у (designation)